Temperature activated electrical circuit closing device



Jline 25, 1957 c. R. BERRY 2,797,282

TEMPERATURE ACTIVATED ELECTRICAL CIRCUIT CLOSING DEVICE Filed Jan. 12, less INVENT OR ATTORNEYS Uite States Patent TEMPERATURE ACTIVATED ELECTRICAL CIRCUIT CLOSING DEVICE Cleveland R. Berry, Conway, Ark.

Application January 12, 1956, Serial No. 558,634

1 Claim. (Cl. 200-138) The present invention is related to electrical circuit makers and is more particularly concerned with a device for completing an electrical circuit upon the surrounding atmosphere reaching a given temperature.

The principal object of the invention is to provide a device for closing an open electrical circuit to operate signals, alarms or the like whenever the device is subjected to a temperature exceeding a given degree and which device can be easily and quickly manually reset returning the electrical circuit to its open condition.

A further and equally important object of the invention is to provide an economically producible temperature controlled circuit maker in which the temperature responsive elements thereof are exposed to the surrounding atmosphere and the temperature variations thereof for being changed thereby and the closing of the circuit is effected by positive acting elements of the circuit maker.

Further objects of the invention will be in part obvious and in part pointed out in the accompanying description of the drawings, in which- Fig. l is a side elevation of the present device.

Fig. 2 is a top plan view thereof.

Fig. 3 is a longitudinal section taken on line 3-3 of Fig. 2.

Fig. 4 is a sectional view of the thermostat controls taken on line 4-4 of Fig. 1.

Fig. 5 is a cross sectional view taken on line 5--5 of Fig. 3.

Fig. 6 is also a cross sectional view, but taken on line 66 of Fig. 1; and

Fig. 7 is a horizontal section taken on line 7-7 of Fig. 3.

Referring now more particularly to the accompanying drawings wherein like and corresponding parts are indicated by similar reference characters, numeral 1 refers to the perforated base of a supporting body of electrical insulating material which base has a flat bottom permitting the same to be mounted upon a supporting surface, which surface should be substantially horizontal.

From base 1 extends an upright portion 2 of said body which has opposing slots 3, 4, 5 and 6 extending through the sides thereof and communicating with a circular bore 7 extending downwardly from the top of said upright portion 2.

A pair of spaced apart electrical contact elements 8 and 9, each having a configuration of a quarter sphere, are positioned in the base of said bore 7 and fastened to said uprights by screws 10 and 11 respectively, while the ends of wires 12 are each connected to one of said screws and extend through one of said slots for example slot 3. The contacts 8 and 9 as well as screws 10 and 11 are of an electrical current conducting material and are positioned for receiving a ball 13 also of current conducting material so that the ball bridges the gap between said contacts and/ or said screws.

Support 2 has a lateral extension 14 from the sides of which extend a pair of spaced apart substantially parallel side walls 15 and 16 with a channel 17 provided in said extension between said side walls which channel slants downwardly towards and communicates with bore 7. A bolt 18 extends through and between side walls 15 and 16 and is retained by head 19 against wall 16 and nut 20 against wall 15. A fork 21 of substantially U-shaped configuration has a pair of fingers 22 and 23 providing a channel therebetween and which fingers extend in line with channel 17. Said fork is mounted at a medial portion thereof upon bolt 18 so that said fork is free to pivot in. a vertical plane. A threaded opening 24 is provided through the base end portion of said fork and has an adjustment screw 25 extending therethrough in threaded engagement therewith.

Said lateral extension 14 of said body has a heat activated element connected to the free end thereof and any of a number of such elements can be employed, but as an example of one such element, there is shown a U-shaped band 26 supporting a superimposed series of bi-metallic cup shaped discs 27 which have a rod 28 mounted on the top thereof for being raised and lowered by said discs upon their expansion and contraction with changes in the temperature of the atmosphere surrounding the same. A cap 29 is mounted upon said extension 14 and extends across the open top of said band 26 and is connected thereto for supporting said band. Rod 28 bears against the central portion of said cap which can be moved by said rod as the central portion of the cap is slightly flexible for this purpose. The lower end of screw 25 bears upon the upper surface of the central portion of said cap.

In the operation of the present device, wires 12 are part of an electrical circuit connected to signals, alarms or the like and which circuit is normally closed except for the space between the contacts 8 and 9 to which said wires are attached. As shown in Figs. 1 and 2, ball 13 is placed upon the space between fingers 22 and 23, and is restrained at the base end thereof due to the ball being seated in the opening 30 provided by bolt 18 and said fingers. Screw 25 is rotated for positioning fork 21 into a substantially horizontal position whereby the ball 13 will tend to remain in said opening. Should the atmosphere surrounding disc 27 reach a given temperature due to the presence of excessive heat, such as a fire or electrical short circuit or the like, discs 2'7 will expand a given distance for which they have been calibrated pushing rod 28 upwardly flexing cap 29 and raising screw 25. Thus fork 21 will pivot about bolt 18 until said fork extends downwardly towards bore 7. When said fork 21 is thus pivoted a sufficient distance, ball 13 will roll from its seat within opening 30 between fingers 22 and 23 and drop down to channel 17 where it will be guided to bore 7. Upon the ball reaching the bottom of said bore, it will assume the position shown in Fig. 3 contacting screws 10 and 11 and/or the contacts 8 and 9 closing the circuit of wires 12 so that current will pass through said circuit to activate signals or alarms for indicating the presence of the excessive temperature. When the excessive temperature has been removed, discs 27 will contract lowering bolt 28 and fork 24 whereupon ball 13 can be lifted from within bore '7 by inserting fingers through some of said slots 3, 4, 5 and 6 and lifted outwardly for being replaced upon fork 24 until again moved by the presence of a temperature exceeding a given degree. Removal of ball 13 from contacts 8 and 9 again opens the electrical circuit stopping the signals or alarms.

In order that the present device is properly balanced, upright 2 extends from the left hand portion of base 1, while lateral extension 14 extends above the right hand portion of said base so that upright 2 ofisets the weight of a thermostatic device, but permits the thermostat device to be exposed for the free passage of .air therearound so that the same will have extreme sensitivity as to variations in the temperature of the surrounding atmosphere.

The present device is capable of considerable modification and such changes thereto as come Within the scope of the appended claim are deemed to be parts of the invention.

What I claim is:

A temperature activated electrical circuit closing device comprising a ball of current conducting material, a supporting base capable of being mounted on and attached to a substantially horizontal surface, an upright of electrical insulating material connected to and extending from said base, said upright having a recess opening at the top of said upright capable of receiving said ball therein and positioned for extending substantially perpendicular to the horizontal surface supporting said base, an arm extending laterally from said upright and spaced above said base, said arm having a channel extending towards and being in communication with said upright recess, a fork pivotally mounted on said arm in line with said channel and capable of retaining said ball when positioned substantially horizontal and guiding said ball to said channel when pivoted towards said channel and means expandable by its surrounding atmosphere reaching a given temperature, connected to said arm and freely exposed to the surrounding atmos phere, a member carried by said fork movable by the expansion of said means for tilting said fork whereby said ball is directed to said arm channel into said upright recess and a pair of electrical spaced contacts are mounted in said upright recess for connection in an electrical circuit and capable of being bridged by said ball for closing said circuit.

References Cited in the file of this patent UNITED STATES PATENTS 1,125,059 Carroll et al. Jan. 19, 1915 1,190,205 Storey July 4, 1916 1,749,775 Millar Mar. 11, 1930 2,191,247 Brandon Feb. 20, 1940 

